Lateral shifting caster truck



Dec. 28, 1948.

R. A1 sHlELns LATERAL SHIFTING CASTER.v TRUCK 4 Sheets-Sheet 1 Filed Dec. 10, 1943 INVENTOR De- 28, 19,48. R. A. sl-nELDs LATER-AL SHIFTING CASTER TRUCK 4 Sheets-Sheet 2 INVENTOR klhhm.

Filed neo. 1o, H1943 R.' A. SHIELDS LATERAL SHIFTING CASTER TRUCK Dec. 28, 194s.

4 Sheets-Sheet 3 Filed Dec. 10, 1943 INVENTOR -ff/@0% Dec. 28, 1948. R. A. SHIELDS LATERAL SHIFTING CASTER TRUCK Filed Dec. 1o, 1943 4 Sheets-Sheet 4 INVENTOR Patented Dec. 28, 1948 2,457,783 LATERA'L SHIFTING CASTER TRUCK Robert A. Shields, Bloomsburg, Pa., assignor to f American Car and Foundry Company, New

York, Y., a corporation of New Jersey Application December 1o, 1943, serial No. 513,694

rlhis invention relates to caster trucks in general and in particular to such trucks for use with mine or other industrial cars which must operate on sharp curves.`

When cars with the Vconventional caster truck are operated on extremely sharp curves derailments occur. Such derailments are due to the fact that the centers of turning foi-the truck are independent and are located on a line extending transversely of the body. This means that the trans- -verse line on which the centers of turning are 1oindependent centers, the trucky on the inner-side of the curve must swing faster than the outer truck in order that the axles of each truck be maintained substantially perpendicular to the rail. With conventional caster trucks Since the inner truck can not swing at a faster rate than the outer truck due to the tie bars, the wheels located adjacent the end of the car and on the inner side of the curve are forced off of the'r'ail. It is an object, therefore, of the present invention to provide a caster truck having the parts so positioned and operating as to cause the inner truck to swing through a greater angle than the outer truck.

A further object of the'invention isthe provision of caster trucks which are positively forced outwardly to change the truck gauge in accordance with the degree ofcurvature of the tracks over which they operate. U

A still further object of the invention is `the provision of caster trucks having means to control the trucks at all times and shift them laterally with respect` to the car body and in direct accordance with the degree of track curvature.

A yet further object of the invention is the provision of laterally shifting caster trucks having resilient self-centering means'connected thereto.

Yet another object of the invention is the provision of laterally shifting caster trucks tied together by resilient tie bars for operation in unison while permitting lateral shift. i

These and other objects of the invention will be apparent vto persons skilled in the art `from a study of the following description and accom, panying drawings, in which? l i 1,1 claims. o1. s- 179) "Fig.` 1 is an elevational view of the right end of the car, while 5 Fig. 2 is an elevational view of the leftfend of the car and taken together disclose the entirecar;

Fig. 3 is an elevational view of the improved truck; i

Fig. 4 is a sectional view of the'truCktalsen substantially on line 4`-4 of Fig. 3 but with parts .broken away to better disclose the construction. Fig. 5 is 'a sectional view taken substantially on line 5"-5`of Fig. 4;

Fig. 6 isa sectional View taken substantially on line 6`6 of Fig. 5;

Fig. 7 is a plan view of the -car with portions of the floor broken away to disclose the movement of the trucks and their relationship to the track when on a sharp curve;

" Fig. 8 is a plan view of the top or body carried supporting plate; i

Fig."9 is a plan view of the body carried bottom supporting plate;

Fig. `10 is a plan view of' one of the 'support plates `but disclosing a slight modification;

` Fig. 11 is a plan View similar to Fig. 7 but showing a modification;

Fig. 12 is a sectional view similar to Fig. 4" but disclosing themodification of Fig. 1l, and Fig. 13 is a half elevational view of themodified truck. I

`Referring now to the drawings in detail, it will be seen that the caster trucks have `been shown asapplied to a comparatively large mine car of the rotary dump type. The car is primarilya side carrying car having sidev walls 2 stiiened by top and'bottom chord members 4 and 5 respectively. The side walls are joined by end walls 6 and oor 8, the latter being located in two levels, one comparatively high level being over the trucks and the other low level being between the trucks. The car, as clearly shown, is provided with automatic couplers 9 carried beneath the high level endiloor portionsjby what may be termed draft sills I0. The load istransferred'by the various framing members supporting the floor to the side walls and thence through large gussets l2 located over the truck centers, thus acting in the same manner asdo holsters in large type cars. Located beneath the gussets l2 are generally U- shaped bearing members I4 which are welded or otherwise secured to the car floor and stiffened by means of a transverse rib I5. These bearing members may be termed slide plates and are formed with aflat lower surface l 6 adapted to cooperate wth and bear directly upon a portion of Ithe truck laterto be described. In order tc shown in the figures, particularly 8 and 9, thevv bearing plates I4 and guide plates I8 are provided with curved slots 22 and 24. The se slots are exactly similar and are locatedin vertically aligned relationship, with the slot 22 arranged 'substan-- tially concentric with the inner end of the slotvv 24, while slot 24 is likewise curved substantially concentric with the inner end of slot 22. exact spacing and length of the lslots ischosen in accordance with the service in which the car is to be used, with the degree of curvebeing the main controlling factor. I'

Each truck shown in Figs. 1 vto 7 inclusive is formed of side frames 26 of channel cross section,

with the flanges directed inwardly and deformed so as to permit of welding the ilanges together adjacent the center of the truck. The side frames are supported upon wheels W by means of axles A. Intermediate` the axles the side frames are pierced to receive a horizontal pivot pin 28 passing through the side frames and alsor through a bushi- -ing 29 located between the webs oi the channel truck side frames. The pivot pins extend beyond the side frames and carry adjacent to the frames saddles 30. These saddles are swingably mounted on the pivot pins' and provided with seats for the lower ends of springs 3 l, the upper ends of which bear against a box-like truck bearing member 32. This box-like truck bearing member is formed of an inverted U-shaped pressing, with the. legs' of the U connected by a bottom plate 33. The sides of the bearing member are vertically slotted as' at 34 to permit vertical movement between the bearing structure and thepivot pins. In order' to provide added bearing area and help relieve Wear',

Small guide plates 35 may be welded or otherwise attached to the .Sides ofthe box-like bearing member adjacent the slots, This box-like truck bearing member is formed with a flat top surface 36 adapted to cooperate with surface i6 of the body bearing member and. also with a bottom flat surface 38 adapted to cooperate with the bearing surface 2D of the guide andr control bracket i8. The top and bottom members of the box-like truck bearing are pierced to receive vertically extending bolts all. These bolts not only extend through the truck bearing member,- butk also through the `Slots of thc bearing members carried by the car body. Likewise, they extend through elongated slots 42 cut in the dansesof the truck frame as clearly shown in Fis. 4 in order that the truck may oscillate about thc pvot pin l28. Surrounding the bolts 40 and located in slots 22 and 24 are hardened bushirlgS or rollers 44 (see particularly Fig. 9). In case bushings alone are used, they should be of slightly greater length than the thickness of body bearing members I4 and IB in order that the bolts may loe-tightened without any danger of binding the structure.

The curvature of slots 22 and 24, assisted by the coopera-tion of the` wheels on the rail, is suiiicient t@ normally holdthe trucks in proper position. However, in order to insurey that the bolts 40 and bushings 44 are heldv against the' inner ends of they slots when the car is on tangent track, a re- The l vends of the car.

silient means 46 is provided. This resilient means is pivotally connected by short pins 4l to the inner end of pivot pins 28. The springs 46 of the resilient tie are placed under a slight initial precompression and are so designed as to readily permit separation of the pivot lpins 23. As shown, particularly in Figs. 4, 5 and 9, the resilient tie member extends through slots 49 cut in bracing structure I8 previously referred to. In order to tie the trucks together and cause unequal rates of swinging thereof. as will later be described, a single ti'e bar 50 is pivotally connected as at 5I to each truck, with the pivot-al connection being located preferably on the gauge line of lthe truck. In assembling the trucks on the body, as will later be apparent, it is important that the tie bar 50, Whichis of rigid construction, be located toward the center of the car as is clearly shown in Figs. 1, 2 and '7.

Referring now to Figs. l1, 12 and 13 which disclose a modiiied truck construction, it Iwill be seen that the truck, frame is formed of hat bars 60 welded together at the ends and intermediate their ends by ties El and supported on the usual axles A and wheels W. These flat side frames are pierced to receive a horizontal pivot bin 62. This pivot pin intermediate the side frames carries a spring saddle structure $4 which in turn supports springs 65, These springs support a boxlike truck bearing member 66 Which may be identical in construction to Ithat previously described in connection with Fiss.` 1 to 'I inclusive. This truck bearing structure 66 is pierced to receive the bolts 4l] and will cooperate with the bearing membcrsi4 and i8 exactly as previously referred to inthe description of Figs. 1 to 7. In this ,form of truck the ends of thev adjacent trucks are tied to.- gether by resilient tie bars 68 pivoted tothe trucks by means,4 such as pins 69, located adjacent each end of the truck and preferably on the truck gauge line, These resilient tie members are pro` vided with a spring 10 and may be of any desired ydesign but are preferably formed as ls the tension structure 46 shown in Figs. 4 and 5. These rcF silient tie members, like the centering structure 45, are constructed so that the springs exert a slight constant pressure tending to hold the trucks centered. yet permit their outward shift. ing and for proper operation the springs should be of equal strength so as to permit parallel movement of the trucks.

In certain cases it may be found desirable to provide greater bearing area than can be provided b y bushings 44 and this may be accomplished by useV of slides 'l2 (Fig. 10). In case the slides are used the slots 22 and 24 must, of course, be elongated to accommodate the slides. While the one rigid tie bar and a resilient centering means has been shown connected to the truck of Figs. 1 to 'Lit iS to be understood that this structure could likewise be used with the truck frame of Figs. 11 to 13, while the resilient tie bars of the latter igures' could be usedV with the truck struce ture of Figs. 1 to '7 inplace of the rigid tie bar and resilient centering means. Likewise, the slides of Fig. 10 or the bushings of Fig. 9 could be used with eitherv type of truck.

The operation of the structure of Figs. 1 to 9 inclusive is as follows and assuming the trucks to be in the position shown by full' lines in Figs. 4 and 5 when on tangent level track. Assuming also that the slots 22' are located adjacent the center' of the car and the slots 24 adjacent the When thel car enters a curve the wheel anges will cause the trucks to swing te. the. outer ends,- tlteseef n l. belts are] snewn tnett nennen. residen with til tsnelsndins'entensenttends. When have 20 everftnstrnelesvlnesss estetneye es l? tdt te .ne endetslet. 2:2@ the tenetsense. here sented e. dis-tenes thet. ees-efe.. el. tdnsteen. feet.. tenes eentess is; to eseeete eyes e assenti-inserte et. eighteen feetzftlie distante 'ftiilrneed te be, approximately ene end e. tali inches. Since thisdlstanee er' lateral shift. ef. the'ttnels essere et enen. side of. the ser., the intresse in. trusts sense will. ter these.` eendltiens total three infants;` The term tenet, sensef as no deed nete and elsewhere tney lee denne'd the. distance between the vertical limesv iolrllgdlb mi?. intersestien. el yerteal planes. Pessina thtdnsh the transverse end le tn dlnel center-mss. of.

ridlnstbe rails. `e pushed the. entre.. which w11.l.., el. edities., sense. the. Wheels, di. the. trusts.. riding the is to be vunderstood, however, that= sveglin ber 5d present er snedtd. deep from, the ser, still. the tenets would. swing' dse, to the eneesenient between the, wheels adiaeent. eentel: eitlle eer. with tlielnner rails Swine se. ef; the tenets ley the. wheel denses vill. eens. tenet. sense te leistete.,eV and s. .es thetrnek, sense intresses the. wheels. edleeent. the. 0f. die ser will seperate edite. rapidly due. te. the test.; that tie est, 5U, eenneets the. inner ends. el; tfnek trenes, that. is in. the.eneinnleeteyssinee they ere' tied. together. by tie red. 5.0.. and. t t'fdelt senee'nereeses. three. insbes. die. the edieeen't the. ends ef' the will; lee essere. d eenresnnntely sin ineltes. ever their eendttlen Sten. dessinent.' elf the tenets .l ter llyf. teeetser with the deed tie bar, will @enseresednelsvinelne @if the tenets endtrlnet. ey.v.heels tethe nesltien. sleewn in Fis. la It.. will. bessen thatth Wheels are all well on the rails andthre, een-lee ln i fel1enee ef derellnlentldnrs. the lateral shifting ofthetrucks due to their swing; ing the tension` structure 4Q connecting pins 28 will lee stretched in. dlreet.. proportion. te. the. ernennt Of' swinging eff the. tieeks. Since this... tension willbe applied olf; center to the 4Q Weide; ere ententes "en the. inner ends. Qi; siete. 2*; end: 22s the trucks. Wilt. Constantly lee., ended; tewerdtheirnormelstraight-enses@ ssen.. It. will leeetvleds tnet tlie. nennenV Posities ef; braking1 thrusts or shocks transmitted to the 10. tte

trod.:- in a lensitddinaldirection, will be abserbed by the sides of slots 22 and 2,4. VShilev any shocks which. may he transmitted. between. the trdeks and leeds ln a transverse dlreeten will be, teens.- Iditted te. thelnner ends enly ef the slots., since, all. sneh sheeks must be transmitted through the. Wheel flense- It will. else. lee Obi/inns theft, due. te the converging enrvetnre ef slots 22. end. 24, even iff the. tension. structures 46 er the resilient bers e8,.- were.. elltnlneted, still the trdelss Wedld. .59 rei'full.; it? @fr @131.1911 POSQIL. i011 as* s. .Ins a belt. 40. te. be, in the enter end et slet .22s it, will, be .lnisesslble fertne belt .riding in t 2-4. to. nieve Qutveardly. 'llleteiere` fer; ene ef; .swingt-ne the. belts in slots 24 ere nt dentelfs .fer the. trnek, While in the 9i@ (itoll Q Swingingom. 110111131., me. bolts in slots 22 become the apparent centers.

Referring now to the modied form of Figs, 1l. te .1.31. lt will be. seen tnet the trneks swine ln accordance Wit the curve and shift the trucks laterally in. neeetdenee with the entve eXeetly as has been previously described. In this case, novi/fever, thc yresilient tie bars. 68, are substituted for the single, `rigid tive. bar 50 and the centering means 4,6. `In case: the tension means 'N1 are of substantially equal strength, then the trucks will remain' substantiallyV parallel during their lateral shift andv the parts will be brought to the positions shownin- Eig. 11 disclosing the car on a.,oonilparativr-:ly` sharp` curve. It is obvious that, lff desired. the Wheels edleeent the ends ef. the cai; and riding the inner rails may be brought elnsente these tnils, by melting the tenslen springs in; @jacent lie-93319615 0f) the., @al $1gm1y: lIIQngel' than the springs adjacent the outer ends ot the car. This will in elect give a position ofthe inner truckon the rail intermediate the position shown in Fig. 7 and that shown in Fig. 11'.

Whilethe increase in truck gauge has been accomplished by use of curved slots, it is obvious that other means for positively shifting the trucks toincrease the truck gaugemay be used and also it Will be` obvious that various forms of tie bars,

other than those shown, to control thel rate of the swinging of the truck-s maybe used. Accord ingly, while. the. invention has been described with reference to. specific illustrations, it is to be understood that various modications and rearrangements ot parts may be made and all such modifications 'and rearrangements of parts are contemplated as will fall within the scope of the appended claims dening my.. invention.

`What is claimed is:

l. yIn a car adapted totravel valong track having curves therein, the. combination with a car body. QI, body bearingv members connected to the car bod-y. adjacent each side thereof, laterally spaced apart trucks sv'vingable. relative to the car body, truck bearing membersI carried by said trucksY and engaging said body bearing membei-ssupport the. car body, saidf bearing.V members being; sol constructed and arranged asv to increase the. truck. gauge.- during swinging of the. trucks on track curves.

y 2,* In anar adapted to. travel along track hav. ing curves therein.` the. combination with a car body of., body bearing members, connected` to` the cai; body adjacent each side thereof, laterally spaced trucks swinsable relative tothe cai: body @permit travel ofthe body around curves in the tr cls, tiguck bearing` members.,carried by saidl s. an-der1g-ging`said body` bearing members .upport the.V car body, and. guidemeans cai.

. byensefsald members end eeenetetlnewl-tn crease the truck gauge during swinging of` the trucks on track curves.

3. In a car adapted to travel along track having curves therein, the combination with a car body of, body bearing members connected to the car body adjacent each side thereof, laterally spaced trucks swingable relative to the car body to permit travel of the body around curves in the track, truck bearing members carried by said trucks and engaging said body bearing members to support the car body, gui-de means carried by one of said members and cooperating with curved slots in the vother of said members to increase the truck gauge during swinging of the trucks on track curves, and resilient means connected to the laterally spaced trucks and constantly urging the same toward a position substantially parallel to the longitudinal center line of the car body.

4. In a car adapted to travel along track having curves therein, the combination with a car body of, body bearing members connected to the car body adjacent each side thereof, laterally spaced trucks swingable relative to the car body to permit travel of the body around curves in the track,gtruck bearing members carried by said trucks and engaging said body bearing members to support the car body, guide means carried by one of said members and cooperating with curved slots in the other of said members to increase the truck gauge during swinging of the trucks on track curves, resilient means connected to the laterally spaced trucks and constantly urging the same toward a position substantially parallel to the longitudinal center line of the car body, and tie bar means connected to the trucks adjacent their inner ends only thereby causing said trucks to swing at different rates when rounding a curve in the track.

5. Ina car adapted to travel along track having curves therein, the combination with a car body of, caster trucks supporting the car body adjacent each corner thereof and swingable relative thereto to permit the car to travel around curves in the track, said caster trucks having a normal truck gauge substantially equal to the track gauge, resilient means connected to said caster trucks and tending to hold the same to their normal truck gauge, means carried by said car body and trucks to increase the truck gauge during swinging vof the trucks in traveling around curves in the track, and rigid tie bar means connected to the trucks adjacent their inner ends and operating to swing the trucks on the inside of the curve through a greater an'gle than is swung by the trucks on the outside of the curve.l

6. In a car adapted to travel along track having curves therein, the combination with a car body of, caster trucks supporting the car body adjacent each corner thereof and swingable relative thereto to permit the car to travel around curves in the track, said caster trucks having a normal truck gauge substantially equal to the track gauge, means carried by the car body and trucks to increase the truck gauge during swinging of the trucks in traveling around curves in the track, and additional means connected to the trucks and causing the trucks on the inside of the curve to swing at a faster rate than those on the outside of the curve.

7. In a car adapted to travel along track having curves therein, the combination with a car body of, caster trucks supporting the car body adjacent each corner thereof and swingable relative thereto to permit the car to travel around curves in the track,r said castertrucks having; a normal truck gauge substantially equal to' the track gauge, means carried by the car body and trucks to increase' the truck gauge during swinging of the trucks in traveling aroundcurves-in the track, and additional means connected to the trucks and causing the trucks on the inside of the curve to swing at a faster rate than those on the outside of the curve, said additional means comprising tie bars connected to said caster trucks adjacent their inner and outer ends and including resilient members of different strengths.

8. In a car adapted to travel along track having curves therein, the combination with a car body of caster trucks supporting the car body adjacent each corner thereof and swingable relative thereto to permit the car to travel around curves in the track, said caster trucks having a normal truck gauge substantially equal to the track gauge, means carried by the car body and trucks to increase the truck gaugeduring swinging of the trucks in traveling around curves in the track, and additional means connected to the trucks and causing the trucks on the inside of the curve to swing at a faster rate than those on the outside of the curve', said additional means comprising unequal strength resilient tie bars permitting the increase in truck gauge and connected to said caster trucks adjacent the inner and outer ends thereof with the resilient tie bars of lesser strength arranged adjacent the outer ends of the trucks. l

9. Ina car adapted to travel along track having curves therein, the combination with a car body of, vertically spaced body bearing members connected to the body adjacent each corner thereof andformed with vertically aligned slots, truck bearing `members interposed between said body bearing members and movable relative thereto, pairs I of vertically extending vbolts extending through said truck bearing members and slots and retaining said bearing members in assembled relation, horizontally extending pivot pins extending through said truck bearing members, and caster trucks supporting said pivotI pins and rockable relative thereto. A

10. In a car adapted to travel along track having curves therein, the combination with a car 4body of, vertically spaced body bearing members connected to the body adjacent each corner thereof and formed with vertically aligned slots, truck bearing members interposed between said body bearingA members and movable relative thereto, pairs of vertically extending bolts eX- tending through said truck bearing members and slots and retaining saidy bearing members in assembled relation, horizontally extending pivot pins extending through said truck bearing members, and caster trucks supporting said pivot pinsl and rockable relative thereto, said aligned slots beingarranged in vertically aligned pairs curved concentric with the inner end of the adjacent pair whereby one of the bolts of each pair will be held at'the inner end of one pair of slots while the other bolt of each pair moves outwardly in the other pair of slots during swinging of the trucks in traveling around track curves.

11. In a car adapted to travel along track having curves therein, the Lcombination with a car body of, vertically spaced body bearing members connected to the body adjacent each corner thereof and formed with vertically aligned slots, truck bearing members interposedbetween said body bearing members and movable relative thereto, vpairs of vertically extending bolts ex- 9 l0 tending through said truck bearing members and REFERENCES CITED Slots and retammg said bearing members 1n as' The following references are of record in the sembled relation, horizontally extending pivot me of this patent: pins extending through said truck bearing members, caster trucks supporting said pivot pins and 5 UNITED STATES PATENTS rockable relative thereto, and resilient means Number Name Date connected to said pivot pins and constantly ex- 207,453 SOllther Aug. 27, 1878 ertng pressure tending to hold said trucks subgg; --a-I --llay 'n ctr-line TY 1 saffl parallel to the longltud al en e 10 2,042,623 Montrose-Oster June 2, 1936 0 e 2,063,545 Flowers Dec. 8, 1936 ROBERT A. SHIELDS. 2,242,851 Flowers May 20, 1941 

